Fuel injection pump



June 1, 1948. F|$K 2,442,488

FUEL INJECTION-PUMP Qriginal Filed May 19, 1941 v 3 Sheets-Sheet l M 2 mK 71- 1.1

I NVE TOR 47 Eowm NFIsK 2i BY ATTZN g June 1, 1948. M, sK 2,442,488

FUEL INJECTION PUMP I Original Filed May 19, 1941 3 Sheets-Sheet 2 /&NVENTOR Dwnv M. F/sK "WWI gm AT TOR HEY June 1, 1948. E. M. FISK FUELmmcnon PUMP 3 Sheets-Shea t 3 Original Filed May 19, 1941 NVENTORfowl/v. M. Fisk ATTORNEY Patented June 1, 1948 2,442,488 FUEL INJECTIONPUMP Edwin M. Fisk, Mission San Jose, Calif.

Original application May 19, 1941, Serial No.

Divided and this application November 15, 1943, Serial No. 510,354

Claims. .(Cl. 103-38) The invention relates to a fuel injection pump forinternal combustion engines of the Dieselcycle type, and thisapplication comprises a division of my application Serial No. 394,097,filed May 19, 1941 which issued into Patent No. 2,334,185 on November16, 1943.

, A general object of the invention is to provide a fuel injection pumpwhich is particularly positive and dependable in its action.

A further object is to provide a fuel injection pump of thereciprocating piston type in which the volume of delivered charges maybe adjustably varied without changing the length of thepiston stroke.

A more specific object is to provide an improved operating and controlmeans for an injector pump of the type described supplying fuel oil tothe cylinders of a multi-cylinder radial engine.

The invention possesses other objects and features of advantage, some ofwhich, with the foregoing, will be set forth or be apparent in thefollowing description of a typical embodiment thereof, and in theaccompanying drawings, in which,

Figure 1 is a fragmentary longitudinal section taken through aDiesel-cycle engine embodying the present features of invention.

Figure 2 is a fragmentary transverse sectional view of the engine takenat the line 2-2 in Figure 1.

Figure 3 is a side elevation of the engine at a reduced scale.

Figure 4 is a fragmentary section taken radially and axially of theengine structure at the line 4-4 in Figure 2.-

For purposes of illustration, the features of present invention areincorporated in the structure of a radial Diesel engine it which isparticularly arranged for use in the propulsion of an aeronauticvehicle. A crankshaft l5 carries a propeller l6 and is arranged to bedriven by.

pistons ll operative in cylinders l8 which radiate from the crankshaftaxis and are connected to the same throw offset or crankpin IQ of theshaft by connecting rods 20, the cylinders being disposed in a commonplane perpendicular to the crankshaft axis. The crankpin l9 may becounter-balanced by weighted shaft extensions extending radially fromthe opposite side of the shaft and spaced axially of the shaft to permitthe operation of the connecting rods 20 between them. The present engineassembly, beingparticularly a Diesel-type engine, includes individualfuel pumps 2i and an air compressor 22 for respectively supplying fueland air to the cylinders,

2 these elements being provided at the opposite end of the engine fromthe propeller l6. An exhaust manifold 23 is provided at the forward endof the engine and behind the propeller IS.

The crankcase assembly comprises a generally drum-shaped structureincluding a tubular peripheral wall 24 coaxial with the shaft axis, andforward and rear end walls 25 and 26 which mount the shaft in suitableantifriction bearings 27 provided at axial openings therethrough. In thepresent structure, the wall 25 is integral with the peripheral wall 24of the crankcase, and these walls are cooperative with the wall 26 todefine the crankcase space in which the crankpin ill of the shaftoperative. As particularly illustrated, a flange 29 extends radiallyinwardly from an intermediate point of the bore of the wall 24,

and the wall 26 is fixed to said flange by means 'of bolts 30. At spacedpoints thereabout laterally of the zone of action of the crankpin, theperipheral crankcase wall 24 is provided with cylinderreceiving openingshaving their axes radial to the shaft axis, mutually co-planar, andequally spaced in their line, said openings being arranged to slidablyand closely receive inner end portions of the cylinders l8.

It will now be noted that the cylinders l8 are alike, comprise separateand replaceable elements of the engine assembly, and are so mounted andsecured at the cylinder-receiving openings that the firing of fuelcharges therein does not produce tensional strains radially of theengine on either the cylinder or crankcase structures. As particularlyshown,'the cylinders i8 comprise like one-piece structures provided withbores having more or less convex closed outer end portions. Electricignition plugs 33 may be provided at said outer portions of the cylinderbores, this providing for the necessary ignition for the starting of theengine while cold. The head end of each piston I1 is appropriatelyshaped for cooperation with the opposed head end of the cylinder cavityto provide the required head clearance, to facilitate the scavenging ofcombustion products, and to effect a desirable turbulence of thesupplied aid to intimately mix it with the injected fuel. Externallythereof, each cylinder l8 provided at its sides and head end withheat-radiating ribs or fins 34, the cylinders thereby being arranged forair cooling.

At a point thereof spaced from its inner end,

each cylinder I8 is provided with a radial flange 4 which is operativeto limit the distance of insertion of the cylinder within acylinder-receiving opening in the crankcase wall 24. The inner faces ofeach said cylinder flange and the opposed outer face portion of the wall24 are-mutually complementary to permit a sealing seating of the flangeagainst the wall 24; as shown, said bearing faces are flat. Ring members58 are mounted on the crankcase wall 24 at opposite sides of theopenings 24 and provide suitably positioned threaded radial bores forreceiving the inner extremities of bolts 31 which are arranged to securethe cylinders to the rings while the inner cylinder portions extendthrough the cylinder-receiving crankcase openings; the present rings asare of T section. As particularly illustrated, a yoke member 58 spansand bears against each cylinder 'at its head end, extends parallel tothe engine axis, and receives a bolt 31 through each of its extremities-48 which threadedly receives the threaded porwhereby said bolts freelyreceive the cylinder between them; this arrangement facilitates abalanced tightening of the bolts which are operative as tension elementsbetween the cylinder head and the rings 38 to seat and secure thecylinder at the cylinder-receiving openings with an adjustable degree ofpressure. Since the rings 35 receive the crankcase wall 24 within theirbores, a tightening of a pair of bolts 31 for a cylinder urges thecylinder inwardly to effect a sealed seating of its flange against theopposed seat on the wall 24 while tending to pull the opposite sides ofthe rings against said wall. The mounted rings 35 may be tied togetherin fixed spaced relation; as shown, spreader sleeves 39 engaged betweenthe rings and passing between adjacent cylinders and axially of theengine receive tie bolts 40 which are engaged with and between theflange portions of the rings.

With all the cylinders fixed on the crankcase in the described manner,it is preferable that the bores of the rings snugly engage the crankcasewhereby the inward bearing and sealing pressure of the cylinder flangesagainst the crankcase may be assured. Under operating conditions. thereaction to a working stroke of a piston will tend to move its cylinderoutwardly in the receiving casing opening to thereby. through the bolts31, urge a pulling away of the rings from the wall 24 at the cylinderbase while pulling the rings toward the wall at its diametricallyopposite side to provide a positive bearing pressure of the ringsthereat. Since each cylinder I8 is held against the crankcase onlythrough the rings 36 and bolts 31 between the rings and other cylinders,their side walls are not subjected to any longitudinal tension by reasonof a firing reaction, and the cylindrical crankcase is simultaneouslysubjected only to compressive forces, with the result that the presentcrankcase and cylinder structures do not receive the repeated tensileshocks which the crankcase and cylinders of an engine having itscylinders fixedly related to the crankcase must experience.

In the present five-cylinder Diesel-type engine,

individual fuel pumps 2| are provided and operated for effecting thedelivery of vaporized fuel to the different cylinders. said pumps beingmounted on the portion of the crankcase wall 24 which extends rearwardlybeyond the wall 25. By particular reference to Figure 2, it will benoted that each pump 2| comprises a piston or plunger 4| operative in auniform bore 42 provided in a pump body or barrel 43. A springpressedcheck valve 44 is provided at the discharge end of the bore 42, and aninput duct 45 extends radially to an intermediate point of the tion ofthe pump body 43. A ring member 5| comprising a connection for the tube46 provides a duct 52 terminating in an annular groove in its bore forregistration with the input duct 45 of the body. As particularly shown,the body 48 is stepped to provide a reduced cylindrical portion adjacentits threaded portion for extension through the bore of the member 4|where by said member may be clamped between the cap 48 and the shoulderat the opposite end of the reduced body portion from the threadedportion by reason of the threaded engagement of the body in the cap, theduct 52 then being disposed in the plane of the duct 45.

The mounted pump body 43 extends into the cavity of the pump base member48, and its Diston-receiving bore 42 is long enough to insure a liquidseal of the plunger 4| which is relatively small and rod-like. Thepiston is arranged to constantly extend beyond the body extremity andits extending end carries a contact disc 53. The base portion of themember 48 opposite the cap 48 is provided with an axial bore whichslidably receives a push rod 55 for actuation against the contact head53 of the pump piston 4|, said bore being long enough to insure a solelyrectilinear movement of the push rod. Also, the portion 54 of the member48 has its extremity reduced and threaded for threaded engagement in acomplementary and radially threaded opening in the portion of thecrankcase wall 24 rearwardly of the crankcase and wall 26. In thismanner, the axially aligned push rod 55 and piston 4| extend radially ofthe engine axis, and the piston 4| is movable outwardly in a workingstroke thereof against the resistance of a compression spring 55 whichencircles the pump body portion and piston 4| within the cavity of thebase member 48 and reacts between the inner face of the cap 49 and thedisc 53 to urge a. constant disposal of the pump piston 4| in a limitingwithdrawn position inwardly of the duct 45.

Understanding that the amount of liquid discharged from the pump isdetermined by the distance of working projection of the pump piston 4|beyond the discharge point of the input duct 45, and that the size of acharge must be variable to meet varying load and speed conditions forthe engine, means are provided for varying the charge delivered throughthe check valve 44 at the will of an operator and while the engine isoperating. The present piston actuating means is so operative that thepiston stroke is the same for all of the different fuel charges to beprovided by the pump, the position of the stroke range in the bore 42being varied rather than the actual length of piston stroke.

For producing the two-stroke cycle for which the present engine isdesigned, a plate cam 58 fixed on a rear end extension 58 of the shaftl5 has its cam projection 60 operative in the general plane of the pushrods 55 to successively actuate the pump pistons 4|. Members 6| areconstantly engaged between the cam profile 63 and shoes I! provided onthe inner ends of the push rods 55, said members being shaped anddisposable to vary the distances between the shoes 52 and the camprofile 63 against which the shoes are held by the action of the spring56 to determine the position and range of action of the head end of theplunger 4|. As particularly shown, each member 6| is generallysector-shaped, and has radial edges 64 and 65 substantiallyperpendicular to each other and connected by a curved edge 66.

Links 51 and 68 respectively extend from pivotal connections with themembers 6| provided by corresponding pivot ins 69 and 10, with the pin69 adjacent the intersection point of the edges 84 and 65 while the pin10 is adjacent the intersection point of the edges 65 and 86. The edge66 of each member 81 is curved in the arc of a circle having its centerat the opposite side of the pin 69 from the point of the juncture of theedge 64 with the edge 86; in this manner, the distance from the pin 69to the said member point is less than the distances from the pin 69 tothe point of the member at the juncture of the edges 65 and 66. Withsuch an arrangement, it will be understood that the push rod shoe 52 isfurthest from the pin 69 when the line of the pins 59 and i intersectsthe engine axis, and is nearest to the pivot point 69 when said line ofpivot points is perpendicular to a line through the pivot point and theengine axis.

Each link 61 extends from a pivotal connection with a post 12 projectingtransversely from the casing and wall 26, while each link 68 extendsfrom a pivotal connection with an annular ring 73 which is rotatablymounted on an annular boss 14 on the wall 26. As particularly shown, thelinks Bl comprise pairs of transversely spaced like members whichreceive the members Si between them adiacent the pivot pins 68, whilethe links 68 comprise pairs of transversely spaced like members whichreceive the members 8| between them and are pivoted to the same side ofthe ring l3. Header screws 15 are engaged through arouate slots I6provided in the ring 73 for mounting said ring on the boss M for alimited circumferential shifting thereof. By shifting the ring 13, thepivot points may be variably disposed with respect to the plane of theaxes of the pivot pin 69 and the engine for varying the radial spacingof the push rod shoe 62 from the pivot 69, it being noted that themembers 6| provide cylindrical bearing edge portions which areconcentric with the pivot pins 69, while the shoes 62 are slotted ontheir bearing faces to receive the edges 65.

Means are preferably provided for circumferentially adjusting theposition of the ring 13, and said means is shown as comprising a gear 11engaging a complementary gear portion l8 of the ring 73. The gear ll ismounted on a stem I9 rotatably mounted on and extending transverselythrough a plate 80 which is fixed against the rear extremity of thecrankcase wall 26. As brought out in Figure 4, the outer stem end is ofpolygonal cross-section for engagement by a lever or the end of aflexible shaft (not shown) to rotate the gear '11 and so adjust thepositioning of the members 6i and the working stroke of the piston Al inthe bore a2; this comprises the throttle control for the engine.

An annular-plate 80 closes the rear end of the crankcase wall 2d,comprises the attachin means or base of the rotary air compressor 22,and is secured to the crankcase by the bolts 30. As indicated in Figure1, the bolts 30 may also secure the engine to a mounting frame M for theengine. The shaft extension I! mounts the rotor for the compressor ,andits forward end is splined and pinned within the axial bore of the shaftI! which is tubular for minimizing the weight of the engine.

A charge of liquid fuel discharged by a pump 2| is delivered to anengine cylinder l8 through a. tube 82 to an injector nozzle 83 whichdischarges through an atomizing tip member 34 fixedly (threadedly)mounted in a fuel injection port of the cylinder for delivering anatomized spray of the liquid fuel to the head end of the cylinder. Theinjector nozzle 83 may be of any suitable structure for injecting a fuelcharge into the cylinder. A particularly effective atomizing nozzlestructure is disclosed in my copending application, Serial No. 510,356,filed November 15, 1943, which application also comprises a division ofthe aforesaid application Serial No.. 394,097. It will be understoodthat certain features of the present injector pump 2| are adaptable foruse in liquid-charge devices generally, and that the present disclosuresare therefore not to be considered as limited to a Diesel-cycle radialtype engine.

From the foregoing description taken in connection with the accompanyingdrawings, the advantages of the construction and operation of thepresent device will be readily understood by those skilled in the art towhich this invention appertains. While I have described the features andprinciples of operation of an assembly which I now consider to comprisea preferred embodiment of my invention, I desire to have it understoodthat the showing is primarily illustrative, and that such changes may bemade, when desired, as fall within the scope of th following claims.

I claim:

1. In an injector pump, a barrel providing a piston bore, a plungeroperative as a piston in said bore, a liquid inlet port at anintermediate point of the bore, a cam shaft providing a cam, a singleactuator member constantly and directly r engaged with and between theplunger and cam for the driving of the plunger from the cam anddisposable to variably space the plunger and the cam profile, and meansadjustable to adjust the operative disposition of said actuator memberbetween the plunger and cam whereby to adjustably vary the range of theplunger stroke in the bore without changing the length of the plungerstroke imposed by the cam.

2. In an injector pump, a barrel providing a piston bore, a liquid inletport at an intermediate point of the bore, a plunger operative as apiston in said bore to deliver a liquid charge to the nozzle at eachactuation thereof and in accordance with the distance of its projectionbeyond the inlet port, a shaft fixedly related to said barrel andproviding a plate cam, a single member directly engaged between theplunger and cam for actuating the plunger from the cam and movabletherewith, means constantly operative upon the plunger to maintain itsengagement with the members and the engagement of the member with thecam profile, said member being adjustably rockable in its plane andshaped to differently space its points of engagement with the plungerand cam in its different adjusted positions, links cooperatively andpivotally securing the member in its operative position between theplunger and camand between fixed and movable elements whereby a movementof the movable element is arranged to rock the member in its plane tochange the mutual spacing of the rod and cam for changing the range ofoperation oi the plunger in the bore without chi-118 8 the workingstroke 01' the plunger produced by the cam, and means adjustable toadjust the setting of the movable element for varying the fuel chargedelivered by the pump at each actuation thereof.

3. In an injector pump. a barrel providing a piston bore. a. liquidinlet port at an intermediate point of the bore, a plunger operative asa piston in said bore to deliver a fuel charge to the nozzle at eachactuation thereof and in accordance with the distance of its projectionbeyond the inlet port, a shaft fixedly related to said barrel andproviding a plate cam, an actuator member of general sector form havingradial side edges connected by an arcuate edge and interposed betweenthe cam and the plunger with its apical point slidably engaging the camedge and its arcuate edge ortion slidably engaging the plunger at pointsin the axial line of the plunger, 9. link pivotally connecting theapical point of the member with a fixed point and extending transverselyof said line, a ring member mounted for circumferential adjustment aboutthe axis of the cam shaft. and a link plvotally connecting a point ofthe member spaced radially of said apical point with said ring memberwhereby a circumferential adjustment of the ring is arranged to changethe spacing of the engaged plunger point and the cam profile, and meansadjustable to adjust the positioning of the ring elementcircumferentially thereof.

4. In an injection pump, a barrel providing a piston bore having aliquid inlet port at an intermediate point thereof, a plunger operativeas a piston in said bore. a drive shaft in constantly fixed relation tosaid barrel and providing a. cam, means providing a driving connectionof variable effective length constantly engaged with and between theplunger and cam for the driving of the plunger from the cam in a.working stroke, and means adjustable to adjust the effective length 01said strut connection without change of the length of piston stroke.

5. A structure in accordance with claim 4 such that an adjustment of theen'ective length of the drive connection by the last means is arrangedto simultaneously adjust the timing of the plunger actuation withrespect to the rotative cycle of the cam.

EDWIN M. FISK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,006,977 Woolson June 2, 19352,016,405 Watson Oct, 8, 1935 2,020,624 Thaheld Nov. 12, 1935 2,053,057Woolson Sept, 1, 1936 2,060,003 Decker Nov. 10, 1936

